2 AC Light Dimmer (isolated control)

Another AC light dimmer, but its main difference is its control circuit is isolated to AC line that much safer to use. You can use circuit on both 120V and 220V AC lines.

Part List:

R1, R2 - 120 ohms 1/4W

R3 - 1.2 kilo ohms 1/4W

R4 - 120 ohms 1/2W

Pot1 - 10 kilo ohms potentiometer

Pot2 - 50 kilo ohms potentiometer

LED - any high brightness LED ( if  you forgot pinouts, see LED pinout)

LDR  - any light dependent resistor (LDR)

Q1 - 2N2222, 9013 or similar NPN transistor

C1 - 47nF mylar or ceramic capacitor rated 600V or higher

C2, C3 - 100nF mylar or ceramic capacitor rated 600V or higher

Diac - HT32 or similar Diac

Triac - BT136, BT139 or similar

Fuse - dependent on the load 

LAMP - filament or incandescent lamp (220V or 120V)

AC - 120v or 220V AC ( 50Hz or 60Hz)

DC - 6V DC or battery

Similar circuits:
Simple Dimmer circuit - very simple version
Modified 220V dimmer - similar with to the dimmer circuit above

Note: Voltages involve are considered high and can electrocute, thus do not assemble if you don't have experience construction similar circuits. LDR and LED must be enclosed in a box or container that no other light except from the LED.